The use of spiral CT and multi-slice CT or the development of high-speed MRI has made it possible to instantaneously generate 300 or more images by one imaging operation.
In diagnosing such images, a doctor (diagnostician) such as a radiologist uses a high-speed computer environment and displays a plurality of cross section images while switching them at high speed.
A key image or schema (sketch indicating the relationship between an organ and a lesion) which is referred to by a doctor in charge (a physician or the like) is attached to a diagnosis report from the diagnostician.
All 300 or more images can be attached as key images to the above diagnosis report. In this case, however, a large load is imposed on a network or computer and so high-speed display cannot be done sometimes.
Although important images may be selected, it is a painstaking job for the doctor in charge to select key images from 300 or more images. As a simple method, therefore, such images are sometimes simply subsampled at predetermined intervals to about 1/3. However, simply subsampling images in this manner may also simply subsample important images. This may interfere with understanding by the doctor in charge.